Utilization of Peach-palm waste for cost-effective amylase production by Trichoderma stromaticum: Stability and industrial potential

Figures & data

Table 1. Mixture planning carried out different combinations of 1.0% nitrogen sources (cocoa bean peel, peptone, and ammonium phosphate) added to the peach palm waste under SSF by Trichoderma stromaticum AM7 (CCMB617P) at 30 °C for 6 days.

1% of Nitrogen source
Run	Cocoa bean peel (%)	Peptone (%)	Ammonium phosphate (%)	Amylase activity (U/gds)
1	100	0	0	31.0
2	0	100	0	38.0
3	0	0	100	33.0
4	50	50	0	35.7
5	50	0	50	35.3
	0	50	50	40.1
7	33.3	33.3	33.3	40.4
8	33.3	33.3	33.3	39.6
9	33.3	33.3	33.3	47.9

Table 2. Validation test of the proposed experimental model for the variable response of mixture proportions (cocoa bean peel, peptone, and ammonium phosphate) at a final concentration of nitrogen source at 1%.

Run	Factors		Answer
	Cocoa bean peel % (X)	Peptone % (Y)	Ammonium phosphate % (W)	Experimental Amylase activity (U/gds)	Theorical Amylase activity (U/gds)	Recovery (%)
1	20	20	60	34.88	38.8 ± 1.9	89.8
2	0	60	40	38.93	40.1 ± 1.7	96.3
3	0	70	30	42.40	40.4 ± 1.6	104.9

Figure 1. Amylase production by Trichoderma stromaticum under SSF using peach-palm waste with different nitrogen sources at 0.5%: yeast extract (YE), peptone (PP), cocoa bean peel (CBP), soybean meal (SM), ammonium nitrate (AN), ammonium phosphate (AP), ammonium sulphate (AS) at 30 °C by 6 days. The data are presented as the mean of three experiments and mean values followed by different letters (a, b, c, d and e) differ statistically (P < 0.05).

Figure 2. Response surface for mixture design of experiment that optimises, using special cubic model, the proportions between cocoa bean peel, peptone, and ammonium phosphate added to the peach palm waste under SSF by Trichoderma stromaticum AM7 (CCMB617P) at 30 °C for 6 days, for amylase synthesis.

Figure 3. Desirability function applied to mixture design to obtain the optimum values for cocoa bean peel, peptone, and ammonium phosphate proportion added to the peach palm waste under SSF by Trichoderma stromaticum AM7 (CCMB617P) at 30 °C for 6 days, for amylase synthesis.

Figure 4. Effect of pH on Trichoderma stromaticum AM7 amylase activity (a) and stability (b).

Figure 5. Effect of temperature on Trichoderma stromaticum AM7 amylase activity (a) and stability (b).

Table 3. Effect of metal ions and reagents on the enzymatic activity of the amylase of the Trichoderma stromaticum AM7 (CCMB617P).

Metal ions/reagents	Relative activity (%)
*Control	100 ± 0.30
Cu^2+	29.4 ± 0.32
Al^2+	123.6 ± 1.61
Lí^2+	93.3 ± 3.65
Mg^2+	74.2 ± 1.93
Mn^2+	91.8 ± 3.22
Ní^2+	108.8 ± 2.79
Na^2+	61.5 ± 2.36
Ca^2+	90.1 ± 2.90
Co^2+	145.8 ± 2.84
Zn^2+	106.7 ± 0.21
Ag^2+	293 ± 3.97
EDTA	77.5 ± 1.67
**SDS	98.4 ± 1.07
ß-mercaptoethanol	102 ± 1.61

*Control: without the addition of metal ions or reagents. **SDS was added at a concentration of 1%. All metal ions and reagents were used at 5 mmol/L.